1. Field of the Invention
The present invention relates to a tip dresser for cutting and repairing spot welding electrode tips of a pair of electrodes by oppositely positioning the electrodes with the tip dresser therebetween at the time of that the electrode tips have been worn out or damaged.
2. Discussion of the Background
A tip dresser is used to repair electrode tips respectively provided on tip portions of bodies of a pair of spot welding electrodes by oppositely positioning the electrodes with the tip dresser therebetween, rotating cutters of the tip dresser and cutting an edge surface of the electrode tip of each electrode to a proper shape at the time of that the electrode tips have been worn out our damaged. The tip dresser of a conventional type is however made of electrically conductive material. This requires shutting off of electric current of a welding machine to prevent the current from flowing from one electrode to the opposite electrode prior to abutting the electrode tips against the cutters of the tip dresser and cutting the edge surfaces of the electrode tips.
However, the shutting off of the current needs to be carried out in each cutting operation carried out by the tip dresser of the conventional type. This is troublesome and therefore degrades working efficiency.
It is an object of the present invention to provide a tip dresser which is capable of cutting edge surfaces of the electrode tips of a pair of the electrodes oppositely positioned with the tip dresser therebetween, as the electric current continuously flows through the welding machine.